In a mobile communications environment of HSDPA (High Speed Downlink Packet Access), a base station (eNodeB) uses a Channel Quality Indicator (CQI) reported from a mobile station (UE) when scheduling radio resources for the mobile station. Specifically, the mobile station receives a pilot channel and the like from the base station, measures quality information such as a Signal to Interference Ratio (SIR) (S1), and feeds back the CQI to the base station (S2), as shown in FIG. 1. The base station uses the CQIs reported from each mobile station and carries out scheduling such as allocation of appropriate radio resources (See 3GPP TS 25.214, “Physical layer procedures (FDD)”).
Typically, the CQI is 5-bit data. The mobile station can measure the CQI every 2 ms. Therefore, the radio resource of 5 bits/2 ms=2.5 kbps is required for each mobile station in order to report the CQI, if the mobile station reports the CQI at every measurement of the CQI.